Cut the guanciale (or pancetta) into small pieces. Cook in a cold pan over medium heat until crispy and golden. Remove from heat and set aside, keeping some of the fat.
Toast black pepper in a pan for 2-3 minutes, then crush it to release the flavor.
In a bowl, mix the grated cheese, egg yolks and 1 whole egg, black pepper, and a little of the cooked fat. Mix until smooth.
Boil spaghetti in salted water until al dente. Save a cup of pasta water before draining.
Slowly add a bit of pasta water to the egg mixture to warm it up. Then, mix the pasta with the sauce, stirring quickly to create a creamy texture.
